Diaquabis[4-(dimethylamino)benzoato](isonicotinamide)zinc(II)

Abstract

The molecule of the title Zn-II complex, [Zn(C9H10NO2)(2)( C6H6N2O)(H2O)(2)], contains two 4-(dimethylamino)benzoate (DMAB) ligands, one isonicotinamide (INA) ligand and two water molecules; one of the DMAB ions acts as a bidentate ligand while the other and INA are monodentate ligands. The four O atoms in the equatorial plane around the Zn atom form a distorted square-planar arrangement, while the distorted octahedral coordination is completed by the N atom of the INA ligand and the O atom of the water molecule in the axial positions. Intramolecular C-H center dot center dot center dot O hydrogen bonding results in the formation of a six-membered ring adopting an envelope conformation. The dihedral angle between the carboxyl groups and the adjacent benzene rings are 4.87 (16) and 2.2 (2)degrees, while the two benzene rings are oriented at a dihedral angle of 65.13 (8)degrees. The dihedral angle between the benzene and pyridine rings are 11.47 (7) and 74.83 (8)degrees, respectively. In the crystal structure, intermolecular O-H center dot center dot center dot O, O-H center dot center dot center dot N and N-H center dot center dot center dot O hydrogen bonds link the molecules into a supramolecular structure. pi-pi contacts between the pyridine and benzene rings and between the benzene rings [centroid-centroid distances = 3.695 (1) and 3.841 (1) angstrom, respectively] further stabilize the structure. Weak intermolecular C-H center dot center dot center dot pi interactions are also present.